To study the comparative adding effect of 6 commercial vitamin supplements and green grasses, this experiment was conducted with 399 brids of shaver strain leghorn for 8 weeks. Results obtained from present study are summarized as follows: 1. Rate of gain, feed intake and feed efficiency were significantly (p$lt;0.01) improved by the chicks fed ration with vitamin supplements. Certain vitamin supplements had better (p$lt;0.05) effect than the others in the rate of gain and amount of feed required per unit of gain. 2. When vitamin supplements were substituted by green barely or acacia leaf meal, the growth rate was deppressed, although there was no difference in feed conversion rate. 3. It may be concluded that attention should be paid on the selection of commercial vitamin supplements to he used for chickens. It also appeared that rate of gain deppressed when vitamin supplements were added at 4-weeks age or substituted by green grasses at 4-weeks age.